The invention relates to a vessel filling apparatus having load detecting capabilities, commonly known as a weight filler in the art, which fills a vessel having a neck including a flange while measuring its weight by means of a load cell.
A conventional weight filler comprises a plurality of bottle mounts circumferentially spaced apart at an equal spacing around the outer periphery of a revolving body, a plurality of load cells mounted on the revolving body and each connected to one of the bottle mounts to measure the weight of a particular bottle on the bottle mount, and a plurality of filling nozzles mounted above respective bottle mounts, the arrangement being such that as a bottle is fed to each bottle mount, the associated filling nozzle fills the bottle with liquid while measuring the weight thereof by means of the load cell during the time the bottle is conveyed rotatively as the revolving body rotates (see, for example, Japanese Laid-Open Patent Application No. 154, 501/1992).
Resin bottles, in particular, PET bottles which find extensive application as liquid filled vessels are very light in weight and unstable, and thus cannot be rapidly conveyed by using a usual conveyor without undergoing a considerable amount of difficulty. Accordingly, their necks are formed with flanges, which are supported from the underside. Alternatively, their necks are carried by grippers for purpose of conveyance of the bottles.
In a filling system in which the filling operation takes place while the bottle necks are being carried, a bottle which is conveyed on a pneumatic conveyor, for example, has its neck gripped by a gripper of an introduction wheel to be handed over to gripper of a filler where it is rotatively conveyed while a filling nozzle fills it with liquid, and the bottle is then handed over to a bottle processor such as a capper through an intermediate wheel which transfers it while carrying its neck.
After desired processing operations are completed, it is discharged onto a delivery conveyor to be fed to a subsequent step.
A processing system which utilizes neck-carrying conveyance performs the conveyance on the basis of the height of the neck of the resin bottle which is being carried, and exhibits an excellent flexibility in that there is no need for the adjustment of elevations of various processors, conveyor and wheels if it is used with bottles of varying size. However, as mentioned above, the conventional weight filler is constructed such that the measurement and the filling of the bottle take place after it is once placed on the bottle mount connected to the load cell. Accordingly, if the weight filler is assembled into this system, there arises a problem that the bottle which has been subject to the neck-carried conveyance must be once released from the gripper onto the bottle mount. As a consequence, if the conveying and processing system combined with the conventional weight filler is to be used with bottles of varying size, an adjustment of elevation of the conveyor and the like is required, which is difficult to accommodate.
It is an object of the invention to provide a weight filler for use with the conveying and processing system for resin bottles which allows the bottle to be filled with liquid while gripping the bottle neck for conveyance.
Above object is accomplished by the provision of a load cell installed to detect a vertical load, a load applicator projecting horizontally from the load cell, grip means mounted on the load applicator for resiliently carrying the neck of the bottle which is urged in a direction opposite from the direction in which the load applicator projects from the load cell, and a filling nozzle for filling the bottle which is carried by the grip means with liquid, the liquid being filled into the bottle gripped by the grip means in a given amount while detecting the load by means of the load cell.
Above object is also accomplished by the provision of a load applicator provided in a manner projecting from a load cell, grip means mounted on the load applicator so as to be rotatable in a horizontal plane for resiliently gripping a bottle neck, rotation restricting means for maintaining the load applicator and the grip means in a given positional relationship to restrict a relative rotation thereof and for releasing the restriction in response to a load in excess of a predetermined value, and a filling nozzle for filling the bottle gripped by the grip means with liquid, a given amount of liquid being filled into the bottle gripped by the grip means while detecting the load by the means of the load cell.